Hello Uli,

My "calculation" of 40.0787 MHz as being the center of
the LHC RF frequency, taking into consideration both Proton
and Ion operation, is near the bottom of the following file
in the section "LHC Locked Clock Frequency":

http://www.pa.msu.edu/hep/atlas/l1calo/cmx/hardware/details/cmx_ab_clock_gen_and_dist.txt


I like your suggestion of being consistent in specifying our
target center frequency.  I'm happy to move from 40.0787 MHz
to whatever L1Calo decides to use as a target center frequency.

Thank you for the note and bringing up this point.

        Thanks,  Dan
P.S.

The 2 files that I have about LHC RF frequency are in the
following web directory and have filenames beginning with
"lhc_rf_frequency".

http://www.pa.msu.edu/hep/atlas/l1calo/cmx/hardware/components/clock/


On Wed, 1 Oct 2014, Schäfer, Dr. Ulrich wrote:

> Hi Dan
>
> just one more comment:
>
> You are specifying the centre frequency as 40.0787.
> We have so far ordered our crystal oscillators at 40.0789.
> Even though that's just ~5ppm difference (and certainly
> below the precision of our oscillators) I am wondering
> whether we should, for consistency, perhaps aim at the
> same targetfrequency.
>
> Should we then assume that all components in our realm
> be specified to 40.0787 (or multiples) ?
>
> cheers
> Uli